1. Field of the Invention
This invention relates to devices for providing automatic interconnection between a remotely located telephone and one or more lines, and more particularly to providing a means whereby a person can remotely access his home telephone and have his home single telephone line automatically connected with any requested telephone location.
2. Background
It has long been an expressed desire of business men and women, particularly self-employed professionals such as medical doctors and lawyers, to be able to remotely call their office telephone and have their office telephone place long distance or local calls, charging the calls to the office telephone. In response, a number of systems have been devised and marketed over past three decades. A typical prior art system is described in U.S. Pat. No. 4,086,438 issued to D. W. Kahn et al on Apr. 28, 1978. Kahn et al describe a system for automatically providing interconnection among a plurality of telephone lines serving a subscriber station, all under the control of a remotely located caller. While some of the prior art devices use single phone lines, the Kahn et al device advantages over the prior art depend on its complex use of multiple telephone lines. The Kahn et al device itself is exceedingly complex in circuitry, having many components and requiring a significant input power and heat dissipation.
Other telephone interconnection systems such as that described In U.S. Pat. No. 3,689,702 issued to T. E. McCay on Sep. 5, 1972, are able to utilize a telephone subscriber, calling it remotely, and making repeated calls without the caller having to hang up. However, the McCay device can not accept remote caller instruction to make more than one type of phone call. The McCay device is thus limited to essentially a two-way operation, connecting its remote caller to a long distance phone destination.
There is therefore a need for an interconnect device that can automatically provide a three-way interconnection line between a single telephone line, any telephone destination and a remote caller, while under the remote caller's control and which is small in size, high in reliability and low in cost.